Condenser and method of making same



' 1,341,336. no Drawing.

UNITED- STATES PATENT .OFFlCE nyaou uacrnnason, or BOXBUBY, massacnusnrrs, assxenon, BY m'EsNn assren- MENTS, mo MICA connnnsna comranr mn, or nos'ron, mxssacnusn'rrs, a con PORATION OF MASSACHUSETTS.

CONDENSER AND METHOD OF MAKING SAME.

To all'whom it may concern:

. Be it known that I, BYRON MACPHERSON, a citizen of the United States, and resident of Roxbury, in the county of Suffolk and State of Massachusetts, have invented an- Im ro'vement in Condensers and Methods of Ma ing Same, ofwhich the following description, in connection with the accompanying drawings, is aspecification, like letters on the drawings representing like parts.

My present invention relates electrical condensers and more articularl to an improved electrical con en'ser and method of I manufacturing the same for use in higli po tential work,

. To facilitate the manufacturin of. electrical condensers of the plate or s eet' type,

it is necess tito depart from the conventional meth -of maln'ng the pile of mica and foily'paper and foil, etc, impregnating said pile after making m'a bath of wax or other insulating material, or ofmaking a -roll of insulating material and a roll of 1 foil. Such condensers may be satisfactory for use in telephone systems and the like,

, but cannot be made to work satisfactorily. in high otential service, because of theinherent y. weak structure of the. insulation interposed between the foil sheets, and because-of the impossibility of insuring intiate contact between'the insulation and the foil sheets. a ,'.,;I-obviate the difliculties enumerated above b using. the best possible dielectric between t e sheets of foil, mica, and treat the mica in such a way that all minute perforations that may exist are permanently sealed and which treatmentinsures an intimate contact 7 between the mica and foil, then by bulldlng the stack in such a way that each sheet; of

foil is tested as itis placed in. position, the

testing being such-that it is impossible to" .build -.a stackany'way but correctly, and

Specification of Letters Patent.

' stack.

invention therefore, is-

Patented May 25, 1920.

l Application filed November 19. 1819. Serial No. 339,241.

ness, coat or rather, entirely cover the sheets with varnish, or other .suitable insulating material, the varnish filling up and permanently sealing all perforations in the sheets,

,then drying the varnished sheets so as to enable the operator to readily handle the same. The operator now builds up the condenser stack by first taking a sheet of mica, placing a sheet of foil thereon so as toextend over one end thereof, then placing a second sheet of mica on and in alinement with the first said .sheet, then placing a second sheet of foil on the second sheet of mica so as to extend over the end thereof remote from the end of the first mica sheet over which the first foil'sheet extends. This (ill series of operations is continued until the stack is of the required size, or height, As

to insure that sheet is placed correctly in the is made for short circuits an each foil When the stack is completed, it may be placed in an 'inclosing boxbefore being tested, or it may be tested before being put in a box, the test consisting in subjecting the completed stack to the action of an intermittent or' alternating current, the potential being gradually increased from start to finish of the test to a point in excess of that employed in service. During the test, all short-circuits developed are healed, with the assurance that they will not reappear after the condenser has gone into use.

The above-described steps of my improved method may be successfully carried out without the use of machinery, but for economic reasons, I prefer to practice the vaurious steps mechanically, and reference is here made to my copending ap lications Serial No. 339,242, filed Novena er 19, 1919, disclosing an apparatus for conditioning mica sheets, Serial No. 3339,9244: filed l liovem-p. ber 19, 1919, disclosing an apparatus for building up a stack or pile of alternate mica and conducting sheets, and Serlal n1 0,339,243 filed November i9 1, 1919, [disclosingan ap- .paratus for testing" and healing or rehealing any defect in a condenscr'stack due to short circuits therein. The structures disclosed in these applications, while facilitating the practice of my present invention, are not 2 wlgs'sa esseniialtb phe successful practice thereof,

and; I donot wish to be limiteiby the dis- 1 blosure in said applications.

My" vention is further described 5m 5 defined in the-form ofia claim as follows: Thai-improved method of making electrh cal-condensers, which consistsfin building agslf-supporting stack of shegig'sbf dielectrio and; foil, electl'ically each'sheet 1Q bff iI individuall as at isplapedin osition in' the. stack, or'shjort cn'cuits an for vof two subscribing witnesses.

BYRON MACPHERSON.

Witnesses:

AUBREY R. Goonwm, JAMES R. Momma. 

